Flow control valves are typically installed on pipelines, such as municipal water lines, buried several feet under the surface of ground or roadway surface. The use of underground valves has resulted in the use of valve box lid and body assemblies to provide a way of obtaining access to the valves without having to dig down in the earth to uncover the valve.
FIG. 1 shows an example of a prior art underground gate valve assembly, generally designated 100, in conjunction with a prior art valve box assembly, generally designated 102, that extends from the gate valve assembly 100 up to the ground or roadway surface (not shown). The prior art valve box assembly 102 has a valve box 104 that defines an enclosed vertical passageway from the gate valve assembly 100 up to the ground or roadway surface. The valve box assembly 102 also has a valve box body 106 at the upper end of the valve box 104 and a valve box lid 108 that seats on and covers the valve box body 104 so as to normally close the vertical passageway of the valve box 104 at its upper end generally flush with the ground or roadway surface. The valve box lid 108 typically has a central aperture 110 with a plug member 112 inserted therein that is removable in order to accommodate use of an extraction tool to lift and remove the valve box lid 108 from the valve box body 106 at the upper end of the valve box 104.
The prior art gate valve assembly 100 typically has an internal gate valve with a rotatable stem 114 extending vertically upward and having a square nut 116 on its upper end. With the valve box lid 108 removed from the upper end of the valve box body 106, a square socket (not shown) on a lower end of an elongated shaft of a tool (not shown) can be extended by a worker from the ground or roadway surface down through the enclosed vertical passageway of the valve box 104 and into a mating relationship with the square nut 116 in order to rotate the stem 114 to open or close the internal gate valve of the gate valve assembly 100. A rim 118 about a lower end of the valve box 104 is seated and supported upon a circular flange 120 secured (in a manner not shown) about and extending radially outward from an upper region of the gate valve assembly 100 such that the vertical passageway of the valve box 104 is also closed at the lower end of the valve box 104.
During periods of heavy rain, it is possible for water, sand, dirt and mud sediment to enter the valve box body, downward past the periphery of the valve box lid, and gradually fill up the enclosed vertical passageway of the valve box body, making maintenance of and accessibility to the underground valve a large problem. Sand, dirt and/or mud sediment settles and packs tightly over time from each rain making it difficult to remove from inside the valve box body. In emergencies this situation creates serious difficulty in turning off the valve; it can literally take hours of labor and heavy equipment to access and operate the valve. Also, in heavy traffic locations valve box lids have been known to popup or eject from their home position on the upper end of the valve box body, resulting in the valve box lid flipping over and being damaged. Further, the tire of a vehicle driving over a loose lid might create a hazardous situation by propelling the loose lid toward pedestrians and passing vehicles.
Accordingly, there remains a need in the art for an innovation that will overcome deficiencies and problems that remain unsolved.